diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index 497beb5..b28cced 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -13,7 +13,7 @@
 #include "core/fxcrt/span_util.h"
 #include "core/fxge/text_char_pos.h"
 #include "third_party/base/check.h"
-#include "third_party/base/notreached.h"
+#include "third_party/base/check_op.h"
 #include "third_party/base/numerics/safe_conversions.h"
 #include "xfa/fde/cfde_textout.h"
 #include "xfa/fde/cfde_wordbreak_data.h"
@@ -1130,11 +1130,7 @@
     if (it->nStart <= start_idx && start_idx < it->nStart + it->nCount)
       break;
   }
-  if (it == text_piece_info_.end()) {
-    NOTREACHED();
-    return {0, CFX_RectF()};
-  }
-
+  CHECK_NE(it, text_piece_info_.end());
   return {it->nBidiLevel, GetCharRects(*it)[start_idx - it->nStart]};
 }
 
diff --git a/xfa/fgas/crt/cfgas_stringformatter.cpp b/xfa/fgas/crt/cfgas_stringformatter.cpp
index 30d16ec..d073dd7 100644
--- a/xfa/fgas/crt/cfgas_stringformatter.cpp
+++ b/xfa/fgas/crt/cfgas_stringformatter.cpp
@@ -727,8 +727,7 @@
     case CFGAS_StringFormatter::DateTimeType::kTime:
       return CFGAS_StringFormatter::DateTimeType::kTimeDate;
     default:
-      NOTREACHED();
-      return type;
+      NOTREACHED_NORETURN();
   }
 }
 
@@ -740,8 +739,7 @@
     case CFGAS_StringFormatter::DateTimeType::kDate:
       return CFGAS_StringFormatter::DateTimeType::kDateTime;
     default:
-      NOTREACHED();
-      return type;
+      NOTREACHED_NORETURN();
   }
 }
 
diff --git a/xfa/fgas/graphics/cfgas_gegraphics.cpp b/xfa/fgas/graphics/cfgas_gegraphics.cpp
index 591451f..cb2b959 100644
--- a/xfa/fgas/graphics/cfgas_gegraphics.cpp
+++ b/xfa/fgas/graphics/cfgas_gegraphics.cpp
@@ -19,7 +19,6 @@
 #include "core/fxge/cfx_unicodeencoding.h"
 #include "core/fxge/dib/cfx_dibitmap.h"
 #include "third_party/base/check.h"
-#include "third_party/base/notreached.h"
 #include "xfa/fgas/graphics/cfgas_gecolor.h"
 #include "xfa/fgas/graphics/cfgas_gepath.h"
 #include "xfa/fgas/graphics/cfgas_gepattern.h"
@@ -129,10 +128,7 @@
 
 void CFGAS_GEGraphics::RestoreGraphState() {
   m_renderDevice->RestoreState(false);
-  if (m_infoStack.empty()) {
-    NOTREACHED();
-    return;
-  }
+  CHECK(!m_infoStack.empty());
   m_info = *m_infoStack.back();
   m_infoStack.pop_back();
   return;
diff --git a/xfa/fwl/cfwl_monthcalendar.cpp b/xfa/fwl/cfwl_monthcalendar.cpp
index 145198b..5867ec9 100644
--- a/xfa/fwl/cfwl_monthcalendar.cpp
+++ b/xfa/fwl/cfwl_monthcalendar.cpp
@@ -50,8 +50,7 @@
     case 6:
       return L"Sat";
     default:
-      NOTREACHED();
-      return L"";
+      NOTREACHED_NORETURN();
   }
 }
 
@@ -82,8 +81,7 @@
     case 11:
       return L"December";
     default:
-      NOTREACHED();
-      return L"";
+      NOTREACHED_NORETURN();
   }
 }
 
diff --git a/xfa/fxfa/cxfa_ffline.cpp b/xfa/fxfa/cxfa_ffline.cpp
index b8f7815..47ebc2e 100644
--- a/xfa/fxfa/cxfa_ffline.cpp
+++ b/xfa/fxfa/cxfa_ffline.cpp
@@ -48,8 +48,7 @@
       case XFA_AttributeValue::Even:
         break;
       default:
-        NOTREACHED();
-        break;
+        NOTREACHED_NORETURN();
     }
   } else if (rect.width < 1.0f) {
     switch (iHand) {
@@ -62,8 +61,7 @@
       case XFA_AttributeValue::Even:
         break;
       default:
-        NOTREACHED();
-        break;
+        NOTREACHED_NORETURN();
     }
   } else {
     switch (iHand) {
@@ -76,8 +74,7 @@
       case XFA_AttributeValue::Even:
         break;
       default:
-        NOTREACHED();
-        break;
+        NOTREACHED_NORETURN();
     }
   }
 }
diff --git a/xfa/fxfa/cxfa_textlayout.cpp b/xfa/fxfa/cxfa_textlayout.cpp
index 10782c0..8228a5c 100644
--- a/xfa/fxfa/cxfa_textlayout.cpp
+++ b/xfa/fxfa/cxfa_textlayout.cpp
@@ -182,8 +182,7 @@
       case XFA_AttributeValue::Radix:
         break;
       default:
-        NOTREACHED();
-        break;
+        NOTREACHED_NORETURN();
     }
     m_pBreak->SetAlignment(iAlign);
 
@@ -715,8 +714,7 @@
         break;
       }
       default:
-        NOTREACHED();
-        break;
+        NOTREACHED_NORETURN();
     }
   }
 
diff --git a/xfa/fxfa/cxfa_textparser.cpp b/xfa/fxfa/cxfa_textparser.cpp
index c503689..15b5178 100644
--- a/xfa/fxfa/cxfa_textparser.cpp
+++ b/xfa/fxfa/cxfa_textparser.cpp
@@ -135,8 +135,7 @@
       case XFA_AttributeValue::Radix:
         break;
       default:
-        NOTREACHED();
-        break;
+        NOTREACHED_NORETURN();
     }
     pStyle->SetTextAlign(hAlign);
     CFX_CSSRect rtMarginWidth;
diff --git a/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp b/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp
index ac68171..96eb05f 100644
--- a/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp
+++ b/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp
@@ -78,7 +78,7 @@
       break;
     }
     default:
-      NOTREACHED();
+      NOTREACHED_NORETURN();
   }
 }